Prodrugs of urolithins and uses thereof

ABSTRACT

The invention provides compounds of formula (I) or salts thereof: 
     
       
         
         
             
             
         
       
         
         
           
             wherein: 
             A, B, C, D, W, X, Y and Z are as defined in the specification, and at least one of A, B, C, D, W, X, Y and Z is OR 1 ; each R 1  being independently H or C(═O)R 2 , and at least one R 1  group being C(═O)R 2 ; where each R 2  is selected from: 
             CHR 3 NHR 4 , where R 4  is H and R 3  is a group selected from CH 3 , CH 2 CH(CH 3 ) 2 , CH(CH 3 )CH 2 CH 3 , CH 2 Ph, CH 2 -3-(1H-indole), CH 2 CH 2 SCH 3 , CH 2 OH, CHOHCH 3 , CH 2 SH, CH 2 SeH and CH 2 PhpOH, 
             wherein said R 3  group can optionally be substituted by one or more groups selected from halogen, cyano, nitro, OR A  or C 1 -C 4  alkyl; 
             or R 3  and R 4  together with the C and N atoms to which they are attached form a 5-membered heteroalkyl ring, wherein said heteroalkyl ring can optionally be substituted by one or more groups selected from halogen, cyano, nitro, OR A  or C 1 -C 3  alkyl, 
             wherein R A  is C 1 -C 4  alkyl optionally substituted with one or more halogen, cyano or nitro groups. 
           
         
       
    
     The compounds are effective pro-drugs for urolithins and they enable the ready delivery of urolithins to the site in the digestive tract where they can be absorbed into the body.

This application is a National Stage Application of PCT/EP2014/079189,filed Dec. 23, 2014, which claims priority to United Kingdom PatentApplication No. 1323008.1, filed Dec. 24, 2013, which is incorporated inits entirety by reference herein.

The current invention relates to derivatives of urolithins and theiruse.

BACKGROUND

Urolithins are metabolites produced by the action of mammalian,including human, gut microbiota on ellagitannins and ellagic acid.Ellagitannins and ellagic acid are compounds commonly found in foodssuch as pomegranates, nuts and berries. Ellagitannins are minimallyabsorbed in the gut themselves. Urolithins are a class of compounds withthe representative structures below and they have been shown to havepotent effects on the improvement of a number of health conditions.

where A, B, C, D, W, X, Y and Z are each independently selected from Hor OH, and at least one of them is OH.

In particular, the compounds Urolithin A and Urolithin B have been shownto be highly biologically active in vitro and in vivo.

Urolithins have been proposed as treatments of a variety of conditionsrelated to inadequate mitochondrial activity, including obesity, reducedmetabolic rate, metabolic syndrome, diabetes mellitus, cardiovasculardisease, hyperlipidemia, neurodegenerative diseases, cognitive disorder,mood disorder, stress, and anxiety disorder; for weight management, orto increase muscle performance or mental performance. See WO2012/088519(Amazentis SA). In WO2007/127263 (The Regents of the University ofCalifornia), the use of urolithins for the treatment of variousneoplastic diseases is described.

International patent publication no. WO2014/004902 (derived fromapplication PCT/US2013/48310) discloses a method of increasingautophagy, including specifically mitophagy, in a cell, comprisingcontacting a cell with an effective amount of a urolithin or apharmaceutically acceptable salt thereof, thereby increasing autophagy,including specifically mitophagy, in the cell. Administration may be toa subject having a disease or condition selected from metabolic stress,cardiovascular disease, endothelial cell dysfunction, sarcopenia, muscledegenerative disease, Duchenne muscular dystrophy, alcoholic liverdisease, nonalcoholic fatty liver disease, drug-induced liver injury,α1-antitrypsin deficiency, ischemia/reperfusion injury, inflammation,aging of the skin, inflammatory bowel disease, Crohn's disease, obesity,metabolic syndrome, type II diabetes mellitus, hyperlipidemia,osteoarthritis, neurodegenerative disease, Alzheimer's disease,Huntington's disease, Parkinson's disease, amyotrophic lateralsclerosis, age-related macular degeneration, mitochondrial diseases(including for example poor growth, loss of muscle coordination, muscleweakness, visual problems, hearing problems, heart disease, liverdisease, kidney disease, gastrointestinal disorders, respiratorydisorders, neurological problems, autonomic dysfunction sometimeslearning disabilities, and dementia as a result of mitochondrialdisease), muscle diseases; sporadic inclusion body myositis (sIBM),cancer, cognitive disorder, stress, and mood disorder.

Whilst urolithin compounds are known to possess properties that renderthem useful in a variety of therapies, they are highly water-insoluble.Consequently, formulation of urolithins into aqueous formulations is notstraightforward. There thus remains a need for compositions ofurolithins that are sufficiently soluble to allow for readyadministration, to provide urolithin that is safe and active in thedesired therapeutic use.

SUMMARY OF THE INVENTION

The invention provides compound of formula (I) or a salt thereof:

wherein:

A, B, C and D are each independently selected from H and OR¹,

W, X and Y are each independently selected from H and OR¹,

Z is selected from H and OR¹;

provided that at least one of A, B, C, D, W, X, Y and Z is OR¹;

each R¹ is independently H or C(═O)R², and at least one R¹ group isC(═O)R²;

each R² is selected from:

CHR³NHR⁴, where R⁴ is H and R³ is a group selected from CH₃,CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-3-(1H-indole), CH₂CH₂SCH₃, CH₂OH,CHOHCH₃, CH₂SH, CH₂SeH and CH₂PhpOH,

wherein said R³ group can optionally be substituted by one or moregroups selected from halogen, cyano, nitro, OR^(A) or C₁-C₄ alkyl;

or R³ and R⁴ together with the C and N atoms to which they are attachedform a 5-membered heteroalkyl ring,

wherein said heteroalkyl ring can optionally be substituted by one ormore groups selected from halogen, cyano, nitro, OR^(A) or C₁-C₃ alkyl,

wherein R^(A) is C₁-C₄ alkyl optionally substituted with one or morehalogen, cyano or nitro groups.

The invention also provides a compound of formula (Ia) or a salt thereoffor use as a medicament:

wherein:

A, B, C and D are each independently selected from H and OR¹,

W, X and Y are each independently selected from H and OR¹,

Z is selected from H and OR¹;

provided that at least one of A, B, C, D, W, X, Y and Z is OR¹;

each R¹ is independently H or C(═O)R², and at least one R¹ group isC(═O)R²;

each R² is selected from:

CHR³NHR⁴ where R⁴ is H and R³ is a group selected from CH₃, CH₂CH(CH₃)₂,CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-3-(1H-indole), CH₂CH₂SCH₃, CH₂OH, CHOHCH₃,CH₂SH, CH₂SeH and CH₂PhpOH,

wherein said R³ group can optionally be substituted by one or moregroups selected from halogen, cyano, nitro, OR^(A) or C₁-C₄ alkyl,

or R³ and R⁴ together with the C and N atoms to which they are attachedform a 5-membered heteroalkyl ring, wherein said heteroalkyl ring canoptionally be substituted by one or more groups selected from halogen,cyano, nitro, OR^(A) or C₁-C₃ alkyl, wherein R^(A) is C₁-C₄ alkyl,optionally substituted with one or more halogen, cyano or nitro groups.

The invention further provides a compound of formula (Ia) or a saltthereof for use as a medicament wherein W, X and Y are H, A, B and C areH, and D and Z are both OR¹, and

each R¹ is independently H or C(═O)R², and at least one R¹ group isC(═O)R²;

each R² is selected from:

CHR³NHR⁴ where R⁴ is H and R³ is selected from H or a group selectedfrom CH₃, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-3-(1H-indole),CH₂CH₂SCH₃, CH₂OH, CHOHCH₃, CH₂SH, CH₂SeH and CH₂PhpOH,

wherein said R³ group can optionally be substituted by one or moregroups selected from halogen, cyano, nitro, OR^(A) or C₁-C₄ alkyl,

or R³ and R⁴ together with the C and N atoms to which they are attachedform a 5-membered heteroalkyl ring, wherein said heteroalkyl ring canoptionally be substituted by one or more groups selected from halogen,cyano, nitro, OR^(A) or C₁-C₃ alkyl, wherein R^(A) is C₁-C₄ alkyl,optionally substituted with one or more halogen, cyano or nitro groups.

The compounds of the invention are more water soluble than theunderivatised urolithins. The current inventors have demonstrated that,under relevant conditions, including when orally administered, they arehydrolysed to release the urolithin portion of the compound, which isbioavailable. The compounds are thus effective pro-drugs for urolithinsand they enable the ready delivery of urolithins to the site in thedigestive tract where they can be absorbed into the body. The compoundsare sufficiently stable to enable delivery, but they are sufficientlysusceptible to hydrolysis to enable delivery of the urolithin portion tothe bloodstream before the compound is excreted from the body.

The invention therefore further provides compounds of formula (I) or(Ia) or salts thereof for use in the treatment of a disease or conditionselected from the group consisting of metabolic syndrome, reducedmetabolic rate, metabolic stress, cardiovascular disease, endothelialcell dysfunction, sarcopenia, muscle degenerative disease, Duchennemuscular dystrophy, alcoholic liver disease, non-alcoholic fatty liverdisease (NAFLD), Nonalcoholic steatohepatitis (NASH), drug-induced liverinjury, drug-induced cravings, anaemia disorders, α1-antitrypsindeficiency, ischemia/reperfusion injury, inflammation, aging of theskin, inflammatory bowel disease, Crohn's disease, obesity, metabolicsyndrome, type II diabetes mellitus, hyperlipidemia, osteoarthritis,neurodegenerative disease, Alzheimer's disease, Parkinson's disease,Huntington's disease, anxiety disorder, ulceration, amyotrophic lateralsclerosis, age-related macular degeneration, mitochondrial diseases(including for example poor growth, loss of muscle coordination, muscleweakness, visual problems, hearing problems, heart disease, liverdisease, kidney disease, gastrointestinal disorders, respiratorydisorders, neurological problems, autonomic dysfunction sometimeslearning disabilities, and dementia as a result of mitochondrialdisease. Further diseases related to mitochondrial dysfunction include:Diabetes mellitus and deafness (DAD); Leber's hereditary opticneuropathy (LHON); Leigh syndrome (subacute sclerosing encephalopathy);neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP);myoneurogenic gastrointestinal encephalopathy (MNGIE); MyoclonicEpilepsy with Ragged Red Fibers (MERRF); Mitochondrial myopathy,encephalomyopathy, lactic acidosis, stroke-like symptoms (MELAS); andmtDNA depletion), sporadic inclusion body myositis (sIBM), cancer,cognitive disorder, stress, and mood disorder; for improving cognitivefunction; for weight management; or to increase muscle or mentalperformance. The compounds of formula (I) or (Ia) or salts thereof areparticularly suitable for use in improving muscle function, musclestrength, muscle endurance and muscle recovery.

In particular, the invention therefore further provides compounds offormula (I) or (Ia) or salts thereof for use in the treatment of adisease or condition selected from the group consisting of metabolicsyndrome, reduced metabolic rate, metabolic stress, cardiovasculardisease, endothelial cell dysfunction, sarcopenia, muscle degenerativedisease, Duchenne muscular dystrophy, alcoholic liver disease,nonalcoholic fatty liver disease, drug-induced liver injury,drug-induced cravings, anaemia disorders, α1-antitrypsin deficiency,ischemia/reperfusion injury, inflammation, aging of the skin,inflammatory bowel disease, Crohn's disease, obesity, metabolicsyndrome, type II diabetes mellitus, hyperlipidemia, osteoarthritis,neurodegenerative disease, Alzheimer's disease, Parkinson's disease,anxiety disorder, ulceration, amyotrophic lateral sclerosis, age-relatedmacular degeneration, cancer, cognitive disorder, stress, and mooddisorder; for improving cognitive function; for weight management; or toincrease muscle or mental performance.

The invention further provides compounds of formula (I) or (Ia) or asalt thereof for use in the treatment of a disease or condition selectedfrom the group consisting of metabolic stress, sarcopenia, muscledegenerative disease, Duchenne muscular dystrophy, alcoholic liverdisease, nonalcoholic fatty liver disease, drug-induced liver injury,α1-antitrypsin deficiency, ischemia/reperfusion injury, inflammatorybowel disease, Crohn's disease, Alzheimer's disease, Parkinson'sdisease, amyotrophic lateral sclerosis, and cancer.

The invention further provides compounds of the formula (I) or (Ia) orsalts thereof for increasing autophagy or mitophagy in a cell.

The compounds of formula (I) or (Ia) may exist in the form of salts, andsuch salts form part of this invention. Further, the compounds may existin the form of solvates, for example hydrates, and solvates should alsobe understood to fall within the scope of this invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the stability of the compound of Example 1 in solution overtime.

FIG. 2 shows the stability of the compound of Example 2 in solution overtime.

FIG. 3 shows the stability of the compound of Example 3 in solution overtime.

FIG. 4 shows the stability of the compound of Example 4 in solution overtime.

FIG. 5 shows the stability of the compound of Example 1 in solution overtime at two different pHs.

FIG. 6 shows the stability of the compound of Example 5 in solution overtime at two different pHs.

DETAILED DESCRIPTION OF THE INVENTION

The compounds of the invention include at least one ester group—OC(═O)R². On administration, the ester group is hydrolysed in the bodyto urolithin and R²C(═O)OH. The urolithin can then exert its biologicaleffect.

Particularly suitable compounds are compounds in which the varioussubstituents are such that the core part of the compound is anaturally-occuring urolithin. Thus, Z is preferably OR¹. W, X and Y arepreferably all H. Particularly suitable compounds are compounds in whichA, B, C and D are such that the core part of the compound is urolithin Aor urolithin B. That is to say that W, X and Y are preferably all H, theZ is preferably OR¹, and that A, B and C are preferably all H. If A, Band C are all H, D is H and Z is OR¹, then the core part of the compoundis Urolithin B. If A, B and C are all H, and D and Z are both OR¹, thenthe core part of the compound is Urolithin A.

In a Urolithin A compound, both D and Z are OR¹. At least one of the R¹groups is C(═O)R². In one embodiment, one R¹ group is H and the other isC(═O)R²; in another embodiment, both R¹ groups are C(═O)R². In that casethe two R² groups may be the same or different. It is convenient forthem to be the same.

As R² is CHR³NHR⁴, R²C(═O)OH is an amino acid. This is preferably anaturally occurring amino acid. Preferably such groups have thestereochemistry of a naturally occurring amino acid. That is to say thatthey are L-amino acids. For most amino acids this equates to the (S)isomer. For cysteine, the higher ranking of sulphur means that theconfiguration is termed (R). When R⁴ is H and R³ is CH₃, the releasedamino acid is alanine. Pairs of R⁴ and R³ groups give rise to particularamino acids as set out in Table 1.

TABLE 1 released amino acids released Amino R⁴ R³ amino acid acidstructure H CH₃ Alanine

H CH₂CH(CH₃)₂ Leucine

H CH(CH₃)CH₂CH₃ Isoleucine

H CH₂Ph Phenylalanine

H CH₂-3-(1H-indole) Tryptophan

H CH₂CH₂SCH₃ Methionine

H CHOHCH₃ Threonine

H CH₂OH Serine

H CH₂SH Cysteine

H CH₂SeH Selenocysteine

H CH₂PhpOH Tyrosine

R³ and R⁴ together with the C and N atoms to which they are attachedform a 2-pyrrolidine ring Proline

Preferably, R² is CHR³NHR⁴, where R⁴ is H and R³ is selected from CH₃,CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-3-(1H-indole), CH₂CH₂SCH₃, CH₂OH,CHOHCH₃, CH₂SH, CH₂SeH or CH₂PhpOH, or R³ and R⁴ together with the C andN atoms to which they are attached form an unsubstituted 5-memberedheteroalkyl ring. Compounds in which R² is CHR³NHR⁴ where R⁴ is H and R³is selected from CH₃, CH₂CH(CH₃)₂ or CH(CH₃)CH₂CH₃, or in which R³ andR⁴ together with the C and N atoms to which they are attached form anunsubstituted 5-membered heteroalkyl ring have particularly advantageoussolubility and stability properties and they are particularly preferred.

The following compounds in Table 2 can specifically be mentioned.

TABLE 2 Compound Structure Shorthand name 2

Di-alanine - Urolithin A 4

Di-leucine - Urolithin A 5

Leucine - Urolithin B 6

Proline - Urolithin B

The following compounds in Table 3 may also specifically be mentioned.

TABLE 3 Compound Structure Shorthand name 1

Di-glycine - Urolithin A 3

Glycine - Urolithin B

When the urolithin is released following administration, it can exertits biological effects in the body. The R²C(═O)OH acid is also released.It is an important aspect of the present invention that the R² groupsare chosen such that the R²C(═O)OH released is a product with nodetrimental effect on the subject, that is to say, the R²C(═O)OH shouldhave either no biological effect, or only beneficial effects. PreferablyR²C(═O)OH is a compound that is of natural origins and generallyregarded as safe under the GRAS provisions issued by the US Food andDrug Administration.

Formulations and Administrations

The compounds of formula (I) or (Ia) or salts thereof may beadministered to a subject alone or together with at least one otheractive agent or carrier, in any of a variety of ways. For example, theymay be administered orally or parenterally. The subject may be a mammal(including a companion animal), especially a human. The compounds may beformulated as pharmaceutical compositions, or they may be formulated asfoods (including drinks) or dietary supplements. They may also beformulated as powders that are admixed with a food or beverageimmediately before administration or consumption.

As such, the compound can be administered in any of a variety ofsuitable forms, including neat compound, natural foods, processed foods,natural juices, concentrates and extracts. Tablets, capsules, powders,granules, injectable solutions, microcapsules, nano-capsules, liposomes,plasters, inhalation forms, nose sprays, nosedrops, eyedrops, sublingualtablets, and sustained-release preparations, may all be used.

Preferably, oral administration is used, whether as a pharmaceuticalformulation or as a food or dietary supplement. Pharmaceutical dosageforms for oral administration include solid, semi-solid, or liquidforms, such as tablets, capsules, powders, granules, solutions, orsuspensions. Alternative dosage forms for alternative administrationmethods include suppositories, injectable solutions, inhalants, gels,creams, microspheres, implants, and aerosols.

In one preferred embodiment, the compounds of the invention areformulated as foods or dietary supplements, including food additives,food ingredients, functional foods, medical foods, nutraceuticals, orfood supplements. In certain embodiments, compounds of the invention canbe included in nutraceutical or functional beverages of varying volumesto permit the administration of a daily dose in a convenient format.Beverages may include products formulated as gels. As a non-limitingexample, beverages may deliver effective doses in a final volume rangingfrom 5 mL to 1,000 mL, delivered as a single dose or multiple doses.

Compounds of the invention may also be formulated as veterinaryproducts, or as functional foods or beverages, for administration toanimals.

The compounds of formula (I) or (Ia) may be in the form of a salt. Thismay be a pharmaceutically acceptable salt. Suitable salts may forexample be derived from an acid selected from acetic, adipic,benzenesulfonic, benzoic, camphorsulfonic, citric, ethanesulfonic,fumaric, gluconic, glutamic, glycolic, hydrobromic, hydrochloric,lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, oxalic,pantothenic, phosphoric, succinic, sulfuric, tartaric,p-toluenesulfonic, xinafoic (1-hydroxy-2-naphthoic acid),naphthalene-1,5-disulfonic acid and the like. Hydrochloride salts areespecially convenient.

The compounds may also be used in appropriate association with otherpharmaceutically active compounds, or with other food additives. Otherpharmaceutically active compounds which may be co-administered orco-formulated with the compounds of the present invention includerapamycin, resveratrol, metformin, and spermidine.

The compounds may in particular be used in association with an agentthat is useful in the treatment of health conditions involving amitochondrial disorder. Such agents include compounds coenzyme Q10(CoQ10) as ubiquinol, CoQ10 as ubiquinone, riboflavin (vitamin B2),L-creatine, L-arginine, L-carnitine, B50 or B100 (B vitamin complexes),vitamin E, vitamin C, alpha-lipoic acid, and folinic acid (e.g., asleucovorin). Thus the invention provides a combination of a compound ofthe invention with one or more compounds selected from the agents in theprevious sentence.

For oral preparations, the compounds can be used alone or in combinationwith appropriate additives to make tablets, powders, granules orcapsules, for example, with conventional additives, such as lactose,mannitol, corn starch or potato starch; with binders, such ascrystalline cellulose, cellulose derivatives, acacia, corn starch orgelatins; with disintegrators, such as corn starch, potato starch orsodium carboxymethylcellulose; with lubricants, such as talc ormagnesium stearate; and if desired, with diluents, buffering agents,moistening agents, preservatives and flavoring agents.

The compounds can be formulated into liquid preparations by dissolving,suspending or emulsifying them in an aqueous or nonaqueous solvent, suchas vegetable or other similar oils, synthetic aliphatic acid glycerides,esters of higher aliphatic acids or propylene glycol; and if desiredwith conventional additives such as solubilizers, isotonic agents,suspending agents, emulsifying agents, stabilizers and preservatives.The compounds can be utilized in aerosol formulation to be administeredvia inhalation. They can be made into suppositories by mixing with avariety of bases such as emulsifying bases or water-soluble bases.

Unit dosage forms for oral administration such as syrups, elixirs, andsuspensions may be provided wherein each dosage unit, for example,teaspoonful, tablespoonful, tablet or capsule, contains a predeterminedamount of the composition containing one or more compounds of thepresent invention. Similarly, unit dosage forms for injection orintravenous administration may comprise the compound of the presentinvention in a composition as a solution in sterile water, normal salineor another pharmaceutically acceptable carrier, wherein each dosageunit, for example, mL or L, contains a predetermined amount of thecomposition containing one or more compounds of the present invention.

In one embodiment, the compounds are provided as a dietary supplementwhich is provided as a solid, for example as a powder or granules, orliquid suitable for adding by the consumer to a food or beverage. Forexample, the dietary supplement may be in the form of a powder orgranules, to be used by mixing into a beverage, or by stirring into asemi-solid food such as a pudding, topping, sauce, puree, cooked cereal,or salad dressing, for instance, or by otherwise adding to a food ordrink. It may for example be enclosed in a compartment of the packagingand be designed to mix with the food or beverage upon opening just priorto consumption. For example, the compound may be placed in the cap of awater (or other liquid) bottle and released into the beverage uponturning the cap. The compound then dissolves in the beverage just priorto consumption. As such, the compound could be placed in the cap of afood or beverage container for release immediately before consumption,or it may be provided as a separate unit within the packaging of food ordrink. The compound may be provided in a kit together with a food orbeverage container.

Dietary supplements may comprise one or more inert ingredients,especially if it is desirable to limit the number of calories added tothe diet by the dietary supplement. For example, a dietary supplementmay also contain optional ingredients including, for example, herbs,vitamins, minerals, preservatives, enhancers, colorants, sweeteners,flavourants, inert ingredients, and the like. In some embodiments,dietary supplements further comprise vitamins and minerals including,but not limited to, calcium phosphate or acetate, tribasic; potassiumphosphate, dibasic; magnesium; magnesium salts, for example magnesiumsulfate or oxide; salt (sodium chloride); potassium chloride or acetate;ascorbic acid; ferric orthophosphate; niacin, niacinamide; zinc sulfateor oxide; calcium pantothenate; copper gluconate; riboflavin;beta-carotene; pyridoxine hydrochloride; thiamin mononitrate; folicacid; biotin; chromium chloride or picolonate; potassium iodide; sodiumselenate; sodium molybdate; phylloquinone; vitamin D; vitamin D3;vitamin E; vitamin B; cyanocobalamin; sodium selenite; copper sulfate;vitamin A; vitamin C; inositol; potassium iodide; L-tryptophan;nicotinic acid; nicotinamide; omega-3 fatty acid (such as DHA, EPA andALA); anthocyanines; isoflavones; choline; UMP; soy phospholipids;phosphatidyl serine; S-adenosyl-methionine (SAM); acethyl-L-carnitine(ALCAR); magnesium salts; magnesium acetate; magnesium chloride;magnesium citrate; magnesium lactate; magnesium gluconante; andmagnesium pidolate. Thus the invention provides a combination of acompound of the invention with one or more compounds selected from theagents in the previous sentence.

Solutions or suspensions containing compounds of the inventionoptionally comprise one or more flavourings. Flavourings may assist inmaking the solutions in their diluted form for ingestion more palatable.The optimal level of flavouring depends on the intensity of flavourdesired, and the nature and strength of the flavour in question.Sweeteners may also be present. Typical sweeteners include sugar,aspartame, acesulfame potassium (acesulfame K), sucralose and saccharineand combinations thereof. Preservatives may also be added to theformulations to extend product shelf life. Various preservatives areknown for use in liquid oral preparations. Examples of suchpreservatives include calcium disodium EDTA, sodium propyl paraben,methyl paraben, ethyl paraben, propyl paraben, benzyl alcohol andphenoxyethanol. Further preservatives that are known for use in liquidoral preparations (including foods) include benzoic acid, dehydroaceticacid, sorbic acid, Bronopol, propylene glycol and glyceryl triacetate.Alcohols are used as preservatives in some preparations.

If desired, the composition may contain an effervescent, that is, anagent comprising one or more compounds which, act individually ortogether, evolve a gas on contact with water. The gas evolved isgenerally oxygen or, most commonly, carbon dioxide.

Treatments Using Compounds of the Invention

As mentioned above, the invention provides compounds of formula (I) or(Ia) or salts thereof for use in the treatment of a disease or conditionselected from the group consisting of metabolic syndrome, reducedmetabolic rate, metabolic stress, cardiovascular disease, sarcopenia,muscle degenerative disease, Duchenne muscular dystrophy, alcoholicliver disease, nonalcoholic fatty liver disease (NAFLD), Nonalcoholicsteatohepatitis (NASH), drug-induced liver injury, drug-inducedcravings, anaemia disorders, α1-antitrypsin deficiency,ischemia/reperfusion injury, inflammation, inflammatory bowel disease,Crohn's disease, obesity, metabolic syndrome, type II diabetes mellitus,hyperlipidemia, osteoarthritis, neurodegenerative disease, Alzheimer'sdisease, Parkinson's disease, Huntington's disease, anxiety disorder,ulceration, amyotrophic lateral sclerosis, mitochondrial diseases(including for example poor growth, loss of muscle coordination, muscleweakness, visual problems, hearing problems, heart disease, liverdisease, kidney disease, gastrointestinal disorders, respiratorydisorders, neurological problems, autonomic dysfunction sometimeslearning disabilities, and dementia as a result of mitochondrialdisease. Further diseases related to mitochondrial dysfunction include:Diabetes mellitus and deafness (DAD); Leber's hereditary opticneuropathy (LHON); Leigh syndrome (subacute sclerosing encephalopathy);neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP);myoneurogenic gastrointestinal encephalopathy (MNGIE); MyoclonicEpilepsy with Ragged Red Fibers (MERRF); Mitochondrial myopathy,encephalomyopathy, lactic acidosis, stroke-like symptoms (MELAS); andmtDNA depletion), sporadic inclusion body myositis (sIBM), and cancer,cognitive disorder, stress, and mood disorder; for improving cognitivefunction; for weight management; or to increase muscle or mentalperformance. The compounds of formula (I) or (Ia) or salts thereof areparticularly suitable for use in improving muscle function, musclestrength endurance and muscle recovery.

In particular, the invention provides compounds of formula (I) or (Ia)or salts thereof for use in the treatment of a disease or conditionselected from the group consisting of metabolic syndrome, reducedmetabolic rate, metabolic stress, cardiovascular disease, sarcopenia,muscle degenerative disease, Duchenne muscular dystrophy, alcoholicliver disease, nonalcoholic fatty liver disease, drug-induced liverinjury, drug-induced cravings, anaemia disorders, α1-antitrypsindeficiency, ischemia/reperfusion injury, inflammation, inflammatorybowel disease, Crohn's disease, obesity, metabolic syndrome, type IIdiabetes mellitus, hyperlipidemia, osteoarthritis, neurodegenerativedisease, Alzheimer's disease, Parkinson's disease, anxiety disorder,ulceration, amyotrophic lateral sclerosis, and cancer, cognitivedisorder, stress, and mood disorder; for improving cognitive function;for weight management; or to increase muscle or mental performance.

The invention further provides compounds of formula (I) or (Ia) or asalt thereof for use in the treatment of a disease or condition selectedfrom the group consisting of metabolic stress, sarcopenia, muscledegenerative disease, Duchenne muscular dystrophy, alcoholic liverdisease, nonalcoholic fatty liver disease, drug-induced liver injury,α1-antitrypsin deficiency, ischemia/reperfusion injury, inflammatorybowel disease, Crohn's disease, Alzheimer's disease, Parkinson'sdisease, amyotrophic lateral sclerosis, and cancer.

The invention further provides compounds of the formula (I) or (Ia) orsalts thereof for increasing autophagy or mitophagy in a cell. Forexample, the autophagy or mitophagy may be in embryonic stem cells,induced pluripotent stem cells, adult stem cells, differentiated cells,blood cells, hematopoietic cells, epithelial cells, exocrine cells,endocrine cells, connective tissue cells, adipose cells, bone cells,smooth muscle cells, striated muscle cells, nerve cells, sensory cells,cardiac cells, hepatic cells, gastric cells, intestinal cells, pulmonarycells, epidermal (i.e. skin) cells (including keratinocytes andfibroblasts), kidney cells, and germ cells. It may thus for exampletreat or prevent a disease or condition selected from the groupconsisting of metabolic syndrome, reduced metabolic rate, metabolicstress, cardiovascular disease, sarcopenia, muscle degenerative disease,Duchenne muscular dystrophy, alcoholic liver disease, nonalcoholic fattyliver disease, drug-induced liver injury, drug-induced cravings, anaemiadisorders, α1-antitrypsin deficiency, ischemia/reperfusion injury,inflammation, inflammatory bowel disease, Crohn's disease, obesity,metabolic syndrome, type II diabetes mellitus, hyperlipidemia,osteoarthritis, neurodegenerative disease, Alzheimer's disease,Parkinson's disease, anxiety disorder, ulceration, amyotrophic lateralsclerosis, and cancer, cognitive disorder, stress, and mood disorder; orit can assist with weight management, or increase muscle or mentalperformance.

Amongst the neurodegenerative diseases, there may specifically bementioned AIDS dementia complex, Alzheimer's disease, amyotrophiclateral sclerosis, adrenoleukodystrophy, Alexander disease, Alper'sdisease, ataxia telangiectasia, Batten disease, bovine spongiformencephalopathy (BSE), Canavan disease, corticobasal degeneration,Creutzfeldt-Jakob disease, dementia with Lewy bodies, fatal familialinsomnia, frontotemporal lobar degeneration, Huntington's disease,Kennedy's disease, Krabbe disease, Lyme disease, Machado-Joseph disease,multiple sclerosis, multiple system atrophy, neuroacanthocytosis,Niemann-Pick disease, Parkinson's disease, Pick's disease, primarylateral sclerosis, progressive supranuclear palsy, Refsum disease,Sandhoff disease, diffuse myelinoclastic sclerosis, spinocerebellarataxia, subacute combined degeneration of spinal cord, tabes dorsalis,Tay-Sachs disease, toxic encephalopathy, transmissible spongiformencephalopathy, and wobbly hedgehog syndrome. In one embodiment, theneurodegenerative disease is selected from the group consisting ofAlzheimer's disease, amyotrophic lateral sclerosis, Huntington'sdisease, and Parkinson's disease. In one embodiment, theneurodegenerative disease is Alzheimer's disease.

An aspect of the invention is in improving cognitive function. In oneembodiment, the cognitive function is selected from the group consistingof perception, memory, attention, speech comprehension, speechgeneration, reading comprehension, creation of imagery, learning, andreasoning. In one embodiment, the cognitive function is selected fromthe group consisting of perception, memory, attention, and reasoning. Inone embodiment, the cognitive function is memory.

An aspect of the invention is in the treatment of cognitive disorder. Inone embodiment, the cognitive disorder is selected from the groupconsisting of delirium, dementia, learning disorder, attention deficitdisorder (ADD), and attention deficit hyperactivity disorder (ADHD). Inone embodiment, the cognitive disorder is a learning disorder. In oneembodiment, the cognitive disorder is attention deficit disorder (ADD).In one embodiment, the cognitive disorder is attention deficithyperactivity disorder (ADHD).

An aspect of the invention is in the treatment of stress-induced orstress-related cognitive deficit. An aspect of the invention is in thetreatment of a mood disorder. In one embodiment, the mood disorder isselected from the group consisting of depression, postpartum depression,dysthymia, and bipolar disorder. In one embodiment, the mood disorder isdepression. In one embodiment, the mood disorder is dysthymia.

An aspect of the invention is in the treatment of stress-induced orstress-related mood disorder, e.g., dysthymia. An aspect of theinvention is in the treatment of an anxiety disorder. In one embodiment,the anxiety disorder is selected from the group consisting ofgeneralized anxiety disorder, panic disorder, panic disorder withagoraphobia, agoraphobia, social anxiety disorder, obsessive-compulsivedisorder, and post-traumatic stress disorder. In one embodiment, theanxiety disorder is generalized anxiety disorder. In one embodiment, theanxiety disorder is post-traumatic stress disorder.

An aspect of the invention is in the treatment of stress-induced orstress-related anxiety.

An aspect of the invention is in enhancing muscle performance. In oneembodiment, the muscle performance is selected from the group consistingof strength, speed, endurance and recovery. In humans, muscle functiongenerally declines with age starting during the third decade of life;the decline generally accelerates after age 65. An aspect of theinvention is thus in maintaining muscle performance during the agingprocess. The enhancement of muscle performance may be as part of the useof the compounds in sports nutrition, in aiding healthy aging (forexample from age 45 to 65), and in slowing the rate of muscle decline inthose aged over 65 (pre-frail)

An aspect of the invention is in the treatment of a muscle orneuromuscular disease. In one embodiment, the muscle or neuromusculardisease is a myopathy. In one embodiment, the muscle or neuromusculardisease is sarcopenia. In one embodiment, the muscle or neuromusculardisease is sporadic inclusion body myositis (sIBM). In one embodiment,the muscle or neuromuscular disease is a muscular dystrophy. In oneembodiment, the muscle or neuromuscular disease is Duchenne musculardystrophy.

An aspect of the invention is in the treatment of mitochondrial disease.For example, a subject may require treatment of poor growth, loss ofmuscle coordination, muscle weakness, visual problems, hearing problems,heart disease, liver disease, kidney disease, gastrointestinaldisorders, respiratory disorders, neurological problems, autonomicdysfunction sometimes learning disabilities, and dementia as a result ofmitochondrial disease.

Further diseases related to mitochondrial dysfunction include:

Diabetes mellitus and deafness (DAD); Leber's hereditary opticneuropathy (LHON); Leigh syndrome (subacute sclerosing encephalopathy);neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP);myoneurogenic gastrointestinal encephalopathy (MNGIE); MyoclonicEpilepsy with Ragged Red Fibers (MERRF); Mitochondrial myopathy,encephalomyopathy, lactic acidosis, stroke-like symptoms (MELAS); andmtDNA depletion.

Amongst cancers, there can specifically be mentioned solid tumours, forexample prostate cancer, pancreatic cancer and colon cancer.

Dosing of Compounds of the Invention

The optimal dosage will depend upon the intended use of the formulation,and upon the individual subject. Dosing may for example be daily toweekly. In one embodiment, dosing is at least weekly. For example, asubject may receive one dose once weekly, twice weekly, thrice weekly,or every other day. In one embodiment, dosing is at least daily. Forexample, a subject may receive one or more doses daily. It is believedthat dosing for greatest efficacy in humans involves extended, dailyadministration. Where extended use is contemplated, this may include usefor 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months, 4 months, 5months, 6 months, or even longer.

The formulations can be administered to human subjects intherapeutically effective amounts. Typical dose ranges are from about0.01 microgram/kg to about 15 mg/kg of body weight per day. The dosageof drug to be administered is likely to depend on such variables as thetype and extent of the disorder, the overall health status of theparticular subject, the specific compound being administered, theexcipients used to formulate the compound, and its route ofadministration. Routine experiments may be used to optimize the dose anddosing frequency for any particular compound.

In one embodiment, the compound is administered at a concentration inthe range from about 0.001 microgram/kg to greater than about 500 mg/kg.For example, the concentration may be 0.001, 0.01, 0.05, 0.1, 0.5, 1,10, 50, 100 or 500 microgram/kg, or 1, 5, 10, 15, 20, 25, 30, 35, 40,45, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350.0 mg/kg, 400 or450.0 mg/kg, to greater than about 500 mg/kg or any incremental valuethereof. It is to be understood that all values and ranges between thesevalues and ranges are meant to be encompassed by the present invention.

In one embodiment, the compound is administered at a dosage in the rangefrom about 0.2 milligram/kg/day to greater than about 100 mg/kg/day. Forexample, the dosage may be 0.2 to 100, 0.2 to 50, 0.2 to 25, 0.2 to 10,0.2 to 7.5, 0.2 to 5, 0.25 to 100, 0.25 to, 0.25 to 25, 0.25 to 10, 0.25to 7.5, 0.25 to 5, 0.5 to 50, 0.5 to 25, 0.5 to 20, 0.5 to 15, 0.5 to10, 0.5 to 7.5, 0.5 to 5, 0.75 to 50, 0.75 to 25, 0.75 to 20, 0.75 to15, 0.75 to 10, 0.75 to 7.5, 0.75 to 5, 1.0 to 50, 1 to 25, 1 to 20, 1to 15, 1 to 10, 1 to 7.5, 1 to 5, 2 to 50, 2 to 25, 2 to 20, 2 to 15, 2to 10, 2 to 7.5, or 2 to 5, mg/kg/day.

In one embodiment, the compound is administered at a dosage in the rangefrom about 0.25 milligram/kg/day to about 50 mg/kg/day. For example, thedosage may be 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2., 2.5, 2.75,3.0, 3.25, 3.5, 3.75, 4.0, 4.25, 4.5, 4.75, 5, 5.5, 6.0, 6.5, 7.0, 7.5,8.0, 8.5, 9.0, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 49, or 50, mg/kg/day.

For a typical human with a body weight in the range 60 to 90 kg, thesedosages correspond to from 1.2 mg to 9 g/day. Examples of doses includefrom 10 mg to 5 g/day, for example from 50 mg to 2.5 g/day, for examplefrom 100 mg to 2.0 g/day, for example from 100 mg to 1.5 g/day, forexample from 100 mg to 500 mg per day, for example from 200 mg to 1.0 gper day.

In another embodiment, the compound is administered in concentrationsthat range from 0.01 micromolar to greater than or equal to 500micromolar. For example, the dose may be 0.01, 0.02, 0.05, 0.1, 0.15,0.2, 0.5, 0.7, 1, 3, 5, 7, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70,80, 90, 100, 150, 200, 250, 300, 350, 400 or 450 micromolar, to greaterthan about 500 micromolar or any incremental value thereof. It is to beunderstood that all values and ranges between these values and rangesare meant to be encompassed by the present invention.

In yet another embodiment, the urolithin or precursor thereof isadministered at concentrations that range from 0.1 microgram/mL to 500microgram/mL. For example, the concentration may be 0.1, 0.5, 1, 2, 5,10, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300,350, 400 or 450 microgram/mL, to greater than about 500 microgram/mL orany incremental value thereof. It is to be understood that all valuesand ranges between these values and ranges are meant to be encompassedby the present invention.

Preferred compounds of the invention have a solubility of over 0.5mg/mL; more preferred compounds have a solubility of over 1.0 mg/mL;still more preferred compounds have a solubility of over 1.5 mg/mL.Accordingly, the doses mentioned above can be provided in a solution offrom 5 ml to 6 L of solution. For some doses, especially any doserequiring the subject to take more than 1 L of solution, it isconvenient to divide the daily dose into several fractions, to be takenat intervals through the day. For example, a subject may take from 10 mlto 1.5 L of solution as the daily dose, for example from 20 ml to 1 L,for example from 25 ml to 500 ml as the daily dose, for example from 50ml to 350 ml, for example from 100 ml to 500 ml. A dose, which may be adaily dose, may for example be 20 ml, 40 ml, 50 ml, 100 ml, 200 ml, 250ml, 300 ml to 400 ml or 500 ml.

Thus, for example, a solution of a compound of the invention at 1.5mg/mL can be provided in a volume of 100 to 500 ml to provide a dailydose of 150 to 750 mg. A solution of a compound of the invention at 2.0mg/mL can be provided in a volume of 50 to 500 ml to provide a dailydose of 100 to 1000 mg.

When the compound of the invention breaks down in the body of a subjectto provide Urolithin, it provides a lower weight of urolithin to thesubject than the weight of prodrug compound administered. The dose ofurolithin that the subject receives can be calculated based on themolecular weight of the pro-drug compound of the invention and themolecular weight of the particular urolithin compound in question. If aparticular dose of urolithin parent compound is desired, the dose ofpro-drug that should be administered to achieve the dose can becalculated based on the molecular weight of the pro-drug compound of theinvention and the molecular weight of the particular urolithin compoundin question. For example, a dose of urolithin compound of from 100 mg to1.5 g per day may be desired.

The effective amount of the compound will vary depending upon the mannerof administration, the age, body weight, and general health of thesubject. Factors such as the disease state, age, and weight of thesubject may be important, and dosage regimens may be adjusted to providethe optimum response. A therapeutically effective amount of the compoundmay for example range from about 0.001 to 30 mg/kg body weight,preferably about 0.01 to 25 mg/kg body weight, more preferably about 0.1to 20 mg/kg body weight, and even more preferably about 1 to 10 mg/kg, 2to 9 mg/kg, 3 to 8 mg/kg, 4 to 7 mg/kg, or 5 to 6 mg/kg body weight.Treatment may be by way of a single treatment or, preferably, caninclude a series of treatments. In one example, a subject is treatedwith the compound in the range of between about 0.1 to 20 mg/kg bodyweight, once per week for between about 1 to 10 weeks, preferablybetween 2 to 8 weeks, more preferably between about 3 to 7 weeks, andeven more preferably for about 4, 5, or 6 weeks. It will also beappreciated that the effective dosage of the compound may increase ordecrease over the course of a particular treatment.

The following Examples illustrate the invention.

A) Synthesis of Example Compounds

All urolithin-aminoacyl analogues were synthesised according to thegeneral scheme below, where R is the relevant side chain, depending onthe amino acid used.

Example 1: Di-glycine-Urolithin A:8-[(2-Aminoacetyl)oxy]-6-oxo-6H-benzo[c]chromen-3-yl 2-aminoacetatedihydrochloride

i) Preparation of the Intermediate Compound8-[(2-{[(tert-Butoxy)carbonyl]amino}acetyl)oxy]-6-oxo-6H-benzo[c]chromen-3-yl2-{[(tert-butoxy)carbonyl]amino}acetate

Urolithin A (50 mg, 0.22 mmol) was dissolved in dry acetonitrile (4 mL),N-boc-glycine (81 mg, 0.46 mmol), DMAP (13 mg, 0.11 mmol) and EDCI (88mg, 0.46 mmol) were added. The reaction mixture was stirred at roomtemperature overnight. The precipitate formed was collected byfiltration and rinsed with water and dry acetonitrile to give the titlecompound as a white solid. Yield 35 mg (29%). LC purity 92%. MS m/z 431[M+H]⁺−(2×t-Bu).

ii) Preparation of the Final Product

8-[(2-{[(tert-butoxy)carbonyl]amino}acetyl)oxy]-6-oxo-6H-benzo[c]chromen-3-yl2-{[(tert-butoxy)carbonyl]amino}acetate: (30 mg, 0.055 mmol) wassuspended in dichloromethane (4 mL) and trifluoroacetic acid (450 uL)was added. The reaction mixture was stirred for 1 hour and concentrated.The residue was suspended in dichloromethane (4 mL) and concentrated.1.25 M HCl in MeOH (4 mL) was added to the residue followed by 10 dropsof water. The solution was concentrated and the white solid wassuspended in 1.25 M HCl in MeOH (4 mL) and concentrated to give thetitle compound as a white solid. Yield 19 mg (83%). LC purity 95%. MSm/z 343 [M+H]⁺.

Example 2: Di-alanine-Urolithin A:8-{[(2R)-2-Aminopropanoyl]oxy}-6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-aminopropanoate dihydrochloride

i) Preparation of the Intermediate Compound8-{[(2R)-2-{[(tert-Butoxy)carbonyl]amino}propanoyl]oxy}-6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-{[(tert-butoxy)carbonyl]amino}propanoate

Urolithin A (50 mg, 0.22 mmol) was dissolved in dry acetonitrile (4 mL),N-boc-L-alanine (87 mg, 0.46 mmol), DMAP (13 mg, 0.11 mmol) and EDCI (88mg, 0.46 mmol) were added. The reaction mixture was stirred at roomtemperature overnight and the precipitate was collected by filtration,rinsed with dry acetonitrile and dried in vacuo. Yield 48 mg (37%). LCpurity 95%. MS m/z 459 [M+H]⁺−(2×t-Bu).

ii) Preparation of Final Product

8-{[(2R)-2-{[(tert-Butoxy)carbonyl]amino}propanoyl]oxy}-6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-{[(tert-butoxy)carbonyl]amino}propanoate (40 mg, 0.07 mmol) wasdissolved in dichloromethane (3 mL) and trifluoroacetic acid (1 mL) wasadded. The reaction mixture was stirred for 4 hours and was thenconcentrated. The residue was suspended in 1.25 M HCl in MeOH (2 mL) andconcentrated. The white solid was suspended in 1.25 M HCl in MeOH (2 mL)and concentrated to give the title compound. Yield 28 mg (90%). LCpurity 95%. MS m/z 371 [M+H]⁺.

Example 3: Glycine-Urolithin B: 6-Oxo-6H-benzo[c]chromen-3-yl2-aminoacetate hydrochloride

i) Preparation of the Intermediate Compound6-oxo-6H-benzo[c]chromen-3-yl 2-{[(tert-butoxy)carbonyl]amino}acetate

Urolithin B (50 mg, 0.24 mmol) was dissolved in dry acetonitrile (4 mL),N-boc-glycine (45 mg, 0.26 mmol), DMAP (7 mg, 0.06 mmol) and EDCI (50mg, 0.26 mmol) was added. The reaction mixture was stirred for 4 hoursat room temperature. The precipitate formed was collected by filtration,rinsed with acetonitrile and dried in vacuo to give the title compoundas a white solid. Yield 28 mg (32%). LC purity 100%. MS m/z 314[M+H]⁺−t-Bu.

ii) Preparation of Final Compound

6-Oxo-6H-benzo[c]chromen-3-yl 2-{[(tert-butoxy)carbonyl]amino}acetate(25 mg, 0.068 mmol) was dissolved in dichloromethane (3 mL) andtrifluoroacetic acid (1 mL) was added. The reaction mixture was stirredfor 1 hour and was then concentrated. The residue was suspended in 1.25M HCl in MeOH (2 mL) and concentrated. To the residue was added 1.25 MHCl in MeOH (2 mL) and the solution was concentrated to give the titlecompound as a white solid. Yield 17 mg (82%). LC purity 95%. MS m/z 270[M+H]⁺.

Example 4: Di-leucine-Urolithin A:8-{[(2R)-2-Amino-4-methylpentanoyl]oxy}-6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-amino-4-methylpentanoate dihydrochloride

i) Preparation of the Intermediate Compound8-{[(2R)-2-{[(tert-Butoxy)carbonyl]amino}-4-methylpentanoyl]oxy}-6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-{[(tert-butoxy) carbonyl]amino}-4-methylpentanoate

Urolithin A (50 mg, 0.22 mmol) was dissolved in dry acetonitrile (4 mL),N-boc-L-leucine (106.4 mg, 0.46 mmol), DMAP (13 mg, 0.11 mmol) and EDCI(88 mg, 0.46 mmol) were added. The reaction mixture was stirred at roomtemperature for 2 hours. Dichloromethane (40 mL) was added and themixture was washed with 0.1 M HCl (3×), water (2×) and dried (MgSO₄).The solution was concentrated to provide the title compound as a whitesolid. Yield 128 mg (88%). LC purity 95%. MS m/z 499 [M+H]⁺−(2×t-Bu).

ii) Preparation of Final Product

8-{[(2R)-2-{[(tert-butoxy)carbonyl]amino}-4-methylpentanoyl]oxy}-6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-{[(tert-butoxy)carbonyl]amino}-4-methylpentanoate (50 mg, 0.076mmol) was dissolved in dichloromethane (3 mL) and trifluoroacetic acid(1 mL) was added. The reaction mixture was stirred for 2 hours and wasthen concentrated at 0° C. To the residue was added dichloromethane (1mL) and 1.25 N HCl (0.5 mL). The solution was concentrated at 0° C. andthe residue was dissolved in dichloromethane (1 mL) and 1.25 N HCl (0.5mL) was added. The solution was concentrated and the white solid wassuspended in dichloromethane (3 mL) and collected by filtration. Yield20 mg (50%). LC purity 95%. MS m/z 455 [M+H]⁺.

Example 5: Leucine-Urolithin B: 6-Oxo-6H-benzo[c]chromen-3-yl(2S)-2-amino-4-methylphentanoate hydrochloride

i) Preparation of the Intermediate Compound6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-{[(tert-butoxy)carbonyl]amino}-4-methylpentanoate

Urolithin B (50 mg, 0.24 mmol) was dissolved in dry acetonitrile (4 mL),N-boc-L leucine (60 mg, 0.26 mmol), DMAP (7.1 mg, 0.06 mmol) and EDCI(50 mg, 0.26 mmol) were added. The reaction mixture was stirred at roomtemperature overnight. Water was added and the precipitate formed wascollected by filtration and dried in vacuo to give a white solid. Yield65.6 mg (64%). LC purity 97%. MS m/z 370 [M+H]⁺−t-Bu.

ii) Preparation of the Final Product

6-oxo-6H-benzo[c]chromen-3-yl(2S)-2-{[(tert-butoxy)carbonyl]amino}-4-methylpentanoate (36 mg, 0.084mmol) was dissolved in dichloromethane (3 mL) and trifluroacetic acid(0.5 mL) was added. The reaction mixture was stirred for 2 hours and wasthen concentrated at 0° C. The residue was dissolved in dichloromethaneand concentrated followed by addition of 1.25 M HCl in MeOH (0.5 mL).The solution was concentrated, and the white solid was suspended in 1.25M HCl in MeOH (1 mL) and concentrated to give the title compound. Yield26 mg (77%). LC purity 95%. MS m/z 326 [M+H]⁺.

Example 6: Proline-Urolithin B: 6-oxo-6H-benzo[c]chromen-3-yl(2S)-pyrrolidine-2-carboxylate hydrochloride

i) Preparation of the Intermediate Compound 1-tert-butyl2-{6-oxo-6H-benzo[c]chromen-3-yl} (2S)-pyrrolidine-1,2-dicarboxylate

Urolithin B (50 mg, 0.24 mmol) was dissolved in dry acetonitrile (4 mL),N-boc-L proline (56 mg, 0.26 mmol), DMAP (7.1 mg, 0.06 mmol) and EDCI(50 mg, 0.26 mmol) were added. The reaction mixture was stirred at roomtemperature overnight. Water was added and the precipitate was collectedby filtration and dried in vacuo to give title compound as a whitesolid. Yield 57.5 mg (59%). LC purity 100%. MS m/z 354 [M+H]⁺−t-Bu.

ii) Preparation of Final Product

1-tert-Butyl 2-{6-oxo-6H-benzo[c]chromen-3-yl}(2S)-pyrrolidine-1,2-dicarboxylate (41 mg, 0.10 mmol) was dissolved indichloromethane (3 mL) and trifluoroacetic acid (0.5 mL) was added. Thereaction mixture was stirred for 2 hours and concentrated.Dichloromethane was added to the residue and the solution wasconcentrated. The semisolid obtained was dissolved in dichloromethane (1mL) and 1.25 M HCl in MeOH (0.5 mL) was added. The solution wasconcentrated and the residue was suspended in dichloromethane (1 mL) and1.25 M HCl in MeOH (0.5 mL) was added. The solution was concentrated togive the title compound as a white solid. Yield 26 mg (75%). LC purity95%. MS m/z 310 [M+H]⁺.

HPLC Analysis

All HPLC analyses were carried out on a 5 μL sample on an Agilent 1100series HPLC system including HPLC pump, auto injector, column oven andPDA detector with a Waters XBridgeC18, 50×2.1 mm, 5 μm column at atemperature of 40° C. and a flow rate of 0.4 mL/min using the followinggradient:

Mobile phase A: 10 mM ammonium formate at pH 4

Mobile phase B: acetonitrile

0-0.25 min: 5% B

0.25-5 min: From 5% to 100% B

5-6 min: 100% B

6-6.1 min: From 100% to 5% B

6.1-8 min: 5% B

UV detection took place at 215-395 nm, and a summary response of thefull wavelength range was used when calculating the areas under thechromatogram peaks.

B) Solubility Experiments

A maximum amount of each compound was dissolved in 400 μL of phosphatebuffer at pH 4 at room temperature in a filter vial (Agilent 0.45 μm PPMini-UniPrep™). The filtered solutions were analysed by HPLC asdescribed above. The peak area of the substance dissolved in buffer wascompared to that of a standard prepared in DMSO. The solubilities forthe tested compounds are given in Tables 6 and 7.

TABLE 6 Solubility of Urolithin A Compounds Solubility MolecularSolubility Urolithin A Compound (mg/mL) Mass (mM/L) Urolithin A 0.00013228.2 0.0057 Example 1 (Di-glycine - UA) 1.93 342 5.64 Example 2(Di-Alanine - UA) 1.8 370 4.86 Example 4 (Di-Leucine - UA) 2.15 454 4.73

TABLE 7 Solubility of Urolithin B Compounds Solubility MolecularSolubility Urolithin B Compound (mg/mL) Mass (mM/L) Urolithin B 0.00027212.2 0.00127 Example 3 (Glycine - UB) 1.33 269 4.94

In all cases, the substituted urolithin compounds have a solubility atleast 10³ times that of the parent urolithin compound (when consideredon a mass or molar basis). The Di-glycine urolithin A compound(Example 1) is more soluble than the Glycine urolithin B compound(Example 3), possibly due to the presence of an additional solubilisingaminoacyl group. Example 4, Di-leucine urolithin A, is particularlysoluble compared to the parent compound.

C) Stability Experiments

The stability of the compounds in aqueous solution at room temperaturewas measured by dissolving the compounds in phosphate buffer of a pHchosen from 2, 3, 4, and/or 5. The compounds with low water solubilitywere first dissolved in DMSO and then diluted with phosphate buffer tocontain 10% of DMSO. The samples were analysed by HPLC, as describedabove, at time 0 and several times thereafter. The peak area of thesamples at these times were compared to the areas at t=0 to calculatethe percentage remaining of the starting compound.

The solutions were prepared for each of the compounds as set out inTable 8. Plots of the percentage remaining of starting substance overtime for each of the compounds measured are given in FIGS. 1-6, and t₅₀values (time taken for 50% of the starting compound to degrade) aregiven in Table 8.

TABLE 8 Degradation times for various compounds of the invention t₅₀Figure Compound Solution pH (mins) 1 Example 1 Di-glycine - 0.77 mg in 1mL 4 74 Urolithin A 5 Example 1: Di-glycine - 0.16 mg in 1 mL 2 81Urolithin A 5 Example 1: Di-glycine - 0.16 mg in 1 mL 5 27 Urolithin A 2Example 2: Di-alanine - 0.94 mg in 1.8 mL 4 29 Urolithin A (first time)2 Example 2: Di-alanine - 0.33 mg in 0.66 mL 4 31 Urolithin A (secondtime) 2 Example 2: Di-alanine - 0.72 mg in 0.4 mL 4 56 Urolithin A 3Example 3: Glycine - 0.31 mg in 1 mL 4 156 Urolithin B 4 Example 4:Di-leucine - 0.4 mg in 1 mL 4 405 Urolithin A 6 Example 5: Leucine - 0.2mg in 1 mL 2 240 Urolithin B 6 Example 5: Leucine - 0.3 mg in 1 mL 5 125Urolithin B

Degradation is seen to occur more quickly in solution of a higher pH; anapproximate two-fold increase in the rate of degradation of Example 5takes place when the pH of the solution is increased from 2 to 5. At pH4, Example 4 degrades more slowly than Example 3, which in turn degradesmore slowly than Example 1, which in turn degrades more slowly thanExample 2. At pH 2 and pH 5, Example 5 degrades more slowly than Example1.

D) Oral Bioavailability Experiments

The oral bio availability of compounds of the invention can be assessedby orally administering a dose of compound in solution to Sprague-Dawleyrats. Blood samples are collected from each rat before administration,and at intervals up to 24 hours thereafter. The blood samples areanalysed for the plasma concentration of Urolithin. WhenDi-leucine-Urolithin A (Example 4) was given in a dose of 57.82 mg/kg innormal saline solution (0.9% NaCl), and in 15% DMSO, 85% water(containing 0.5% methylcellulose/0.25% Tween 80), it was found thatUrolithin A was present at a mean concentration of 96.9 mg/ml at 15minutes following administration in the case of the saline solution, and42.67 mg/ml in the case of the DMSO/water solution. The Urolithin A wasstill present in the blood at a concentration of 2.6 mg/ml at 12 hoursfollowing administration in the case of the saline solution, and 1.30mg/ml in the case of the DMSO/water solution. The C. and AUC ofUrolithin A were higher when the compound of Example 4 was orallyadministered than when Urolithin A was orally administered. Surpisingly,this revealed that the soluble compound of Example 4 was able to deliverUrolithin A at least as effectively into the blood following oraladministration as when Urolithin A was orally administered.

The experiment shows that the compounds of the invention are convertedin the body into the parent urolithin compound. It further shows,surprisingly, that the compounds of the invention can be orallyadministered in different formulations and can still achieve similarlevels of the urolithin compound in the blood.

CONCLUSIONS

All compounds of the invention tested show an enhanced solubility overthe parent urolithins, and they degrade effectively into the parenturolithins over a t_(1/2) timescale of from 27 to 405 minutes. Thisdegradation occurs effectively when the compounds are administeredorally, and the resulting parent urolithins are bioavailable. Thecompounds of the invention are particularly suitable for use as amedicament or a functional composition in solution.

Our copending patent application No. PCT/US2013/48310 (published asWO2014/004902) contains information useful for the proper understandingof the present invention, and the contents of its description aretherefore incorporated herein in its entirety.

The invention claimed is:
 1. A compound of formula (I) or a saltthereof: wherein:

wherein: A, B, and C are H, D is selected from H and OR¹, W, X and Y areeach independently selected from H and OR¹, Z is selected from H andOR¹; provided that at least one of D, W, X, Y and Z is OR¹; each R¹ isindependently H or C(═O)R², and at least one R¹ group is C(═O)R²; eachR² is selected from: CHR³NHR⁴, where R⁴ is H and R³ is a group selectedfrom CH₃, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-3-(1H-indole),CH₂CH₂SCH₃, CH₂OH, CHOHCH₃, CH₂SH, CH₂SeH and CH₂PhpOH, wherein said R³group can optionally be substituted by one or more groups selected fromhalogen, cyano, nitro, OR^(A) or C₁-C₄ alkyl; or R³ and R⁴ together withthe C and N atoms to which they are attached form a 5-memberedheteroalkyl ring, wherein said heteroalkyl ring can optionally besubstituted by one or more groups selected from halogen, cyano, nitro,OR^(A) or C₁-C₃ alkyl, wherein R^(A) is C₁-C₄ alkyl optionallysubstituted with one or more halogen, cyano or nitro groups.
 2. Thecompound of claim 1, wherein W is H, X is H, Y is H; and Z is OR¹. 3.The compound of claim 1, wherein R² is CHR³NHR⁴ where R⁴ is H and R³ isselected from CH₃, CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, or R³ and R⁴ togetherwith the C and N atoms to which they are attached form an unsubstituted5-membered heteroalkyl ring.
 4. The compound of claim 3, wherein thecompound is selected from:


5. A pharmaceutical composition comprising at least one compound ofclaim 1; and a carrier.
 6. The pharmaceutical composition of claim 5,wherein W, X and Y are H, and D and Z are both OR¹, and each R¹ isindependently H or C(═O)R², and at least one R¹ group is C(═O)R²; eachR² is selected from: CHR³NHR⁴ where R⁴ is H and R³ is selected from CH₃,CH₂CH(CH₃)₂, CH(CH₃)CH₂CH₃, CH₂Ph, CH₂-3-(1H-indole), CH₂CH₂SCH₃, CH₂OH,CHOHCH₃, CH₂SH, CH₂SeH and CH₂PhpOH, wherein said R³ group canoptionally be substituted by one or more groups selected from halogen,cyano, nitro, OR^(A) or C₁-C₄ alkyl, or R³ and R⁴ together with the Cand N atoms to which they are attached form a 5-membered heteroalkylring, wherein said heteroalkyl ring can optionally be substituted by oneor more groups selected from halogen, cyano, nitro, OR^(A) or C₁-C₃alkyl, wherein R^(A) is C₁-C₄ alkyl, optionally substituted with one ormore halogen, cyano or nitro groups.
 7. The pharmaceutical compositionof claim 5, wherein said pharmaceutical composition is in the form of asolution or suspension.
 8. The pharmaceutical composition of claim 5,wherein said pharmaceutical composition is in the form of a powder orgranules suitable for solution or suspension in an aqueous medium. 9.The pharmaceutical composition of claim 5, further comprising a furtheractive ingredient selected from rapamycin, resveratrol, metformin, andspermidine.
 10. The pharmaceutical composition of claim 5, wherein W isH, X is H, Y is H; and Z is OR¹.
 11. A food, beverage or dietarysupplement containing a compound of claim
 1. 12. The food, beverage ordietary supplement of claim 11, which is in the form of a food additive,a food ingredient, a functional food, a medical food, a nutraceutical, afood supplement, a functional beverage, or a gel.